> to be assigned randomly from 169.254.0.0/16

Yes, but the question is, "what if an address in this range is assigned to _two_ interfaces at the same time?" Now your local routing information base cannot distinguish which interface to use when trying to reach other hosts in that same network. So, it's fair to say, it's not a feature even available in IPv4.

The second difference is IPv6 is almost always going to have link local addresses assigned and machines with multiple network interfaces are the norm rather than the exception.